The present invention generally relates to apparatuses and methods employed in the home for laundering clothing and fabrics. More particularly, it relates to a new and improved method and apparatus for home laundering of a fabric load using a wash liquor comprising a multi-phase mixture of a substantially inert working fluid and at least one washing additive.
In the Specification and Claims, the terms "substantially non-reactive" or "substantially inert" when used to describe a component of a wash liquor or washing fluid, means a non-solvent, non-detersive fluid that under ordinary or normal washing conditions, e.g. at pressures of -10 to 50 atmospheres and temperatures of from about 10.degree. to about 45.degree. C., does not appreciably react with the fibers of the fabric load being cleaned, the stains and soils on the fabric load, or the washing additives combined with the component to form the wash liquor.
Home laundering of fabrics is usually performed in an automatic washing machine and occasionally by hand. These methods employ water as the major component of the washing fluid. Cleaning additives such as detergents, enzymes, bleaches and fabric softeners are added and mixed with the water at appropriate stages of the wash cycle to provide cleaning, whitening, softening and the like.
Although improvements in automatic washing machines and in cleaning agent formulations are steadily being made, as a general rule, conventional home laundering methods consume considerable amounts of water, energy and time. Water-based methods are not suitable for some natural fiber fabrics, such as silks, woolens and linens, so that whole classes of garments and fabrics cannot be home laundered, but instead, must be sent out for professional dry cleaning. During water washing, the clothes become saturated with water and some fibers swell and absorb water. After washing, the water must be removed from the clothes. Typically, this is performed in a two-step process including a hard spin cycle in the washer and a full drying cycle in an automatic dryer. The hard spin cycles tend to cause wrinkling which is not wanted. Even after spinning, drying cycle times are undesirably long.
Non-aqueous washing methods employed outside the home are known, but for various reasons, these methods are not suitable for home use. Generally, the non-aqueous washing methods to date employ substitute solvents in the washing fluid for the water used in home laundering.
Conventional dry cleaning methods have employed halogenated hydrocarbon solvents as a major component of a wash liquor. The most commonly used halogenated hydrocarbon solvents used for dry cleaning are perchloroethylene, 1,1,1-trichloroethane and CFC-113. These solvents are ozone depleting and their use is now controlled for environmental reasons. Moreover, many of these solvents are suspected carcinogens that would require the use of a nitrogen blanket. Accordingly these dry cleaning solvents cannot be used in the home.
Alternative dry cleaning methods employed petroleum-based or Stoddard solvents in place of the halogenated hydrocarbon solvents. The petroleum-based solvents are inflammable and smog-producing. Accordingly, their commercial use is problematic and use of these materials in the home is out of the question. U.S. Pat. No. 5,498,266 describes a method using petroleum-based solvents wherein perfluorocarbon vapors are admixed with petroleum solvent vapors to remove the solvents from the fabrics and provide improvements in safety by reducing the likelihood of ignition or explosion of the vapors.
A further non-aqueous solvent based washing method employs liquid or supercritical carbon dioxide solvent as a washing liquid. As described in U.S. Pat. No. 5,467,492, highly pressurized vessels are required to perform this washing method. In accordance with these methods, pressures of about 500 to 1000 psi are required. Pressures of up to about 30 psi are approved for use in the home. The high pressure conditions employed in the carbon dioxide create safety hazards that make them unsuitable for residential use.
Various perfluorocarbon materials have been employed alone or in combination with cleaning additives for washing printed circuit boards and other electrical substrates, as described for example in U.S. Pat. No. 5,503,681. Spray cleaning of rigid substrates is very different from laundering soft fabric loads. Moreover, cleaning of electrical substrates is performed in high technology manufacturing facilities employing a multi-stage apparatus which is not readily adapted for home use.
Accordingly, to overcome the disadvantages of prior art home laundering methods, it is an object of the present invention to provide a new and improved method and apparatus for laundering a fabric load in the home employing a safe and effective, environmentally-friendly, nonaqueous wash liquor.
It is another object of the present invention to provide a new and improved apparatus for laundering a fabric load in the home, which is safe and effective for a broad range of fabric types, including natural fiber fabrics, such as woolens, linens and silks.
It is a further object of the present invention to provide a new and improved home laundering method and apparatus which consumes less water, time and energy than conventional water-based home laundering machines and methods.
It is still another object of the present invention to provide a new and improved dry to dry home laundering method and apparatus requiring less handling by the home user.
It is a further object of the present invention to provide a new and improved home laundering method and apparatus which provides safe and effective fabric cleaning without introducing wrinkling.